The present invention relates to a method and a device for adjusting the length of cut of a chopping device of an agricultural harvesting machine according to the preamble of Claims 1 and 8.
Publication DE 102 20 699 A1 makes known a device that includes a sensor for registering chopped material parameters. Depending on the parameters measured, particularly the moisture content of the crop material, the length of cut of the chopping device is automatically adjusted. It is a disadvantage, however, that the length-of-cut setting selected in this manner does not necessarily indicate whether optimal compression of the crop material can be attained with the least amount of compression effort. This first becomes clear in a subsequent working process, e.g., during silage in the horizontal silo.
In order to nevertheless attain good air exclusion for the fermentation process taking place in the silage, it must be possible to compress the crop material chopped by the chopping device in the silo in an optimal manner. The amount of compression force to be applied depends on the compressibility of the chopped crop material, which, in turn, depends on the length of cut of the crop material. As described above, means for adjusting the length of cut of a chopping device are known, but they do not provide an exact indication of the compressibility of the crop material. It would be feasible to always chop the crop material so finely that a satisfactory level of compressibility would result when the material is dry. A procedure of this type is not economical, however, because energy is wasted when the material is chopped more finely than necessary, and because moist material becomes difficult to handle when it is chopped too finely.